Methods and Apparatuses for Coding and Decoding Depth Map

ABSTRACT

A method for coding and decoding a depth map includes determining to perform simplified depth coding (SDC) decoding according to a flag of an SDC mode, determining a size of an image block and a maximum prediction size, determining an intra-frame prediction mode, in a case in which the size of the image block is greater than the maximum prediction size, splitting the image block to obtain N split image blocks, and performing the SDC decoding on the N split image blocks using the intra-frame prediction mode.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/880,094, filed on Oct. 9, 2015, which is a continuation ofInternational Patent Application No. PCT/CN2014/075239, filed on Apr.14, 2014. The International Application claims priority to ChinesePatent Application No. 201310127421.6, filed on Apr. 12, 2013, andChinese Patent Application No. 201310138110.X, filed on Apr. 19, 2013.All of the aforementioned patent applications are hereby incorporated byreference in their entireties.

TECHNICAL FIELD

Embodiments of the present disclosure relate to the field of wirelesscommunications technologies, and in particular, to methods andapparatuses for coding and decoding a depth map.

BACKGROUND

Three-dimensional video images are classified into two types a viewimage and a depth map. The view image includes information, such ascolor information, of the image itself. The depth map includes depthinformation, such as contour information, of the view image. To reducebandwidth occupied by video transmission during transmission of thethree-dimensional video image, coding processing needs to be performedon the view image and the depth map so as to reduce a data size of thethree-dimensional video image.

Simplified depth coding (SDC) is a method for coding a depth map. In acase in which an image block of the depth map on which the SDC needs tobe performed is determined, a coder needs to select an intra-frameprediction mode and determine prediction data of the image blockaccording to the intra-frame prediction mode. A prediction mode that canbe selected by the coder may be any one of the following modes, a directcurrent mode, a planar (Planar) mode, and a depth modeling mode (DMM),where the DMM includes an explicit wedgelet (Wedgelet) mode, anintra-predicted wedgelet partitioning mode, an inter-componentprediction of wedgelet partitioning mode, and an inter-componentprediction of contour partitioning mode. When determining the predictiondata of the image block according to the intra-frame prediction mode,the coder needs to determine a size of the image block. When the SDC isperformed on the image block, a size of a prediction block on which SDCis performed needs to be consistent with the size of the image block.However, a maximum prediction size (that is, a maximum size of the imageblock on which the SDC is performed) is limited, and the size of theimage block may be greater than the maximum prediction size, forexample, the size of the image block is 64×64, whereas the maximumprediction size is 32×32. In this case, when SDC is performed on theimage block, an image block of a size greater than the maximumprediction size needs to be introduced into a coding and decodingsystem, which may increase design overheads of the coding and decodingsystem. In addition, the DMM does not support the image block of a sizegreater than the maximum prediction size. Therefore, in a case in whichthe size of the image block is greater than the maximum prediction size,the DMM cannot be selected to perform the SDC on the image block,thereby resulting in a decrease in coding efficiency.

SUMMARY

Embodiments of the present disclosure provide methods and apparatusesfor coding and decoding a depth map, which may improve processingefficiency of reconstructing, by a decoder, an image block of a depthmap on which SDC coding is performed.

According to a first aspect, an embodiment of the present disclosureprovides a method for decoding a depth map, where the method includesobtaining a flag of simplified depth coding SDC, and determining toperform SDC decoding, determining a size of an image block and a maximumprediction size, determining an intra-frame prediction mode of the imageblock, when the size of the image block is greater than the maximumprediction size, splitting the image block to obtain N split imageblocks, where a size of the N split image blocks is the same as themaximum prediction size, and performing the SDC decoding on the N splitimage blocks using the intra-frame prediction mode.

With reference to the first aspect, in a first possible implementationmanner, the intra-frame prediction mode that is used when the SDC isperformed on the image block is a depth modeling mode DMM or a planarmode or a direct current mode.

With reference to the first aspect or the first possible implementationmanner, in a second possible implementation manner, the splitting theimage block to obtain N split image blocks according to the size of theimage block and the maximum prediction size, where a size of each of theN split image blocks is the same as the maximum prediction size includessplitting the image block to obtain split image blocks according to thesize of the image block and the maximum prediction size, where if a sizeof the split image blocks is the same as the maximum prediction size,the N split image blocks are obtained, or if a size of the split imageblocks is greater than the maximum prediction size, continuing to splitthe split image blocks until the size of the split image blocks is thesame as the maximum prediction size, and the N split image blocks areobtained.

With reference to the first aspect or either one of the foregoingpossible implementation manners, in a third possible implementationmanner, the performing the SDC decoding on the N split image blocksusing the intra-frame prediction mode includes obtaining N residuals bymeans of decoding when performing the SDC decoding on the N split imageblocks.

With reference to the third possible implementation manner, in a fourthpossible implementation manner, the performing the SDC decoding on the Nsplit image blocks using the intra-frame prediction mode includesdetermining an average value of prediction data of the N image blocksusing the intra-frame prediction mode that is used when the SDC isperformed on the image block, and determining reconstruction values ofthe N image blocks according to the average value of the prediction dataof the N image blocks and the N residuals, so as to complete performingthe SDC decoding on the N image blocks.

With reference to the fourth possible implementation manner, in a fifthpossible implementation manner, the determining an average value ofprediction data of the N image blocks using the intra-frame predictionmode that is used when the SDC is performed on the image block includesobtaining the prediction data using the intra-frame prediction mode thatis used when the SDC is performed on the image block, and determiningthe average value of the prediction data of the N image blocks using thefollowing formula, PV_(i)=ΣPPix_(i)[x,y]/sumOfPPix, where PV_(i) is anaverage value of prediction data of the i^(th) image block among the Nimage blocks, PPix_(i)[x,y] is a pixel value in prediction data whosecoordinates are [x,y] in the i^(th) image block, and sumOfPPix is thenumber of pixels in the i^(th) image block.

With reference to the fourth possible implementation manner, in a sixthpossible implementation manner, the determining reconstruction values ofthe N image blocks according to the average value of the prediction dataof the N image blocks and the residuals of the N image blocks includesdetermining the reconstruction values of the N image blocks using thefollowing formula, R_(i)=PV_(i)+S_(i), where R_(i) is a reconstructionvalue of the i^(th) image block among the N image blocks, PV_(i) is anaverage value of prediction data of the i^(th) image block among the Nimage blocks, and S_(i) is a residual of the i^(th) image block amongthe N image blocks.

According to a second aspect, an embodiment of the present disclosureprovides a method for coding a depth map, where the method includesdetermining a size of an image block and a maximum prediction size,determining an intra-frame prediction mode, when the size of the imageblock is greater than the maximum prediction size, splitting the imageblock to obtain N split image blocks according to the size of the imageblock and the maximum prediction size, where a size of the N split imageblocks is the same as the maximum prediction size, and performingsimplified depth coding SDC on the N split image blocks using theintra-frame prediction mode.

With reference to the second aspect, in a first possible implementationmanner, the intra-frame prediction mode is a depth modeling mode DMM ora planar mode or a direct current mode.

With reference to the second aspect or the first possible implementationmanner, in a second possible implementation manner, the splitting theimage block to obtain N split image blocks according to the size of theimage block and the maximum prediction size, where a size of the N splitimage blocks is the same as the maximum prediction size includessplitting the image block to obtain split image blocks according to thesize of the image block and the maximum prediction size, where if a sizeof the split image blocks is the same as the maximum prediction size,the N split image blocks are obtained, or if a size of the split imageblocks is greater than the maximum prediction size, continuing to splitthe split image blocks until the size of the split image blocks is thesame as the maximum prediction size, and the N split image blocks areobtained.

With reference to the second aspect or either one of the foregoingpossible implementation manners, in a third possible implementationmanner, the performing simplified depth coding SDC on the N split imageblocks using the intra-frame prediction mode includes determining anaverage value of prediction data of the N split image blocks using theintra-frame prediction mode, determining an average value of raw data ofthe N split image blocks, determining residuals of the N split imageblocks according to the average value of the prediction data of the Nsplit image blocks and the average value of the raw data of the N splitimage blocks, and coding the residuals of the N split image blocks, soas to complete performing simplified depth coding SDC on the N splitimage blocks.

With reference to the third possible implementation manner, in a fourthpossible implementation manner, the determining an average value ofprediction data of the N split image blocks using the intra-frameprediction mode includes determining the prediction data of the N splitimage blocks using the intra-frame prediction mode, and determining theaverage value of the prediction data of the N split image blocks usingthe following formula, PV_(i)=ΣPPix_(i)[x,y]/sumOfPPix, where PV_(i) isan average value of prediction data of the i^(th) image block among theN split image blocks, PPix₁ [x,y] is a pixel value in prediction datawhose coordinates are [x,y] in the i^(th) image block, and sumOfPPix isthe number of pixels in the i^(th) image block.

With reference to the third possible implementation manner, in a fifthpossible implementation manner, the determining an average value of rawdata of the N split image blocks includes determining the average valueof the raw data of the N split image blocks using the following formula,BV_(i)=ΣBPix_(i)[x,y]/sumOfBPix where BV is an average value of raw dataof the i^(th) image block among the N split image blocks, BPix_(i)[x,y]is a pixel value in raw data whose coordinates are [x,y] in the i^(th)image block, and sumOfBPix is the number of pixels in the i^(th) imageblock.

With reference to the third possible implementation manner, in a sixthpossible implementation manner, the determining residuals of the N splitimage blocks according to the average value of the prediction data ofthe N split image blocks and the average value of the raw data of the Nsplit image blocks includes determining the residuals of the N splitimage blocks using the following formula, S_(i)=PV_(i)−BV_(i) whereS_(i) is a residual of the i^(th) image block among the N split imageblocks, PV_(i) is an average value of prediction data of the i^(th)image block among the N split image blocks, and BV_(i) is an averagevalue of raw data of the i^(th) image block among the N split imageblocks.

With reference to the second aspect or the first possible implementationmanner, in a seventh possible implementation manner, the method furtherincludes, when the size of the image block is less than or equal to themaximum prediction size, performing simplified depth coding SDC on theimage block using the intra-frame prediction mode.

With reference to the second aspect or any one of the foregoing possibleimplementation manners, in an eighth possible implementation manner, thesize of the image block is a size of a transform block, or the maximumprediction size is a maximum transform size.

According to a third aspect, an embodiment of the present disclosureprovides an apparatus for decoding a depth map, where the decodingapparatus includes a determining unit, configured to determine,according to a flag of simplified depth coding SDC, to use SDC decoding,where the determining unit is further configured to determine a size ofan image block and a maximum prediction size, the determining unit isfurther configured to determine an intra-frame prediction mode that isused when SDC is performed on the image block, and the determining unitis further configured to split the image block to obtain N split imageblocks according to the size of the image block and the maximumprediction size when the size of the image block is greater than themaximum prediction size, where a size of the N split image blocks is thesame as the maximum prediction size, a decoding unit, configured toperform the SDC decoding on the N split image blocks using theintra-frame prediction mode, and a reconstruction unit, configured toreconstruct the image block according to a result of the SDC decodingperformed on the N split image blocks.

With reference to the third aspect, in a first possible implementationmanner, the determining unit is configured to split the image block toobtain split image blocks according to the size of the image block andthe maximum prediction size, where if a size of the split image blocksis the same as the maximum prediction size, the N split image blocks areobtained, or if a size of the split image blocks is greater than themaximum prediction size, continue to split the split image blocks untilthe size of the split image blocks is the same as the maximum predictionsize, and the N split image blocks are obtained.

With reference to the third aspect or the first possible implementationmanner, in a second possible implementation manner, the decoding unit isconfigured to obtain N residuals by means of decoding when performingthe SDC decoding on the N split image blocks.

With reference to the second possible implementation manner, in a thirdpossible implementation manner, the decoding unit is configured todetermine an average value of prediction data of the N image blocks anddetermine residuals of the N image blocks using the intra-frameprediction mode that is used when the SDC is performed on the imageblock, and determine reconstruction values of the N image blocksaccording to the average value of the prediction data of the N imageblocks and the N residuals, so as to complete performing the decoding onthe N image blocks.

With reference to the third possible implementation manner, in a fourthpossible implementation manner, the decoding unit is configured todetermine the prediction data of the N image blocks using theintra-frame prediction mode that is used when the SDC is performed onthe image block, and determine the average value of the prediction dataof the N image blocks using the following formula,PV_(i)=ΣPPix_(i)[x,y]/sumOfPPix where PV_(i) is prediction data of thei^(th) image block among the N image blocks, PPix_(i)[x,y] is a pixelvalue in prediction data whose coordinates are [x,y] in the i^(th) imageblock, and sumOfPPix is the number of pixels in the i^(th) image block.

With reference to the fourth possible implementation manner, in a fifthpossible implementation manner, the decoding unit is configured todetermine the reconstruction values of the N image blocks using thefollowing formula, R_(i)=PV_(i)+S_(i), where R_(i) is a reconstructionvalue of the i^(th) image block among the N image blocks, PV_(i) is anaverage value of prediction data of the i^(th) image block among the Nimage blocks, and S_(i) is a residual of the i^(th) image block amongthe N image blocks.

According to a fourth aspect, an embodiment of the present disclosureprovides an apparatus for coding a depth map, where the coding apparatusincludes a determining unit, configured to determine a size of an imageblock and a maximum prediction size, where the determining unit isfurther configured to determine an intra-frame prediction mode, and thedetermining unit is further configured to split the image block toobtain N split image blocks according to the size of the image block andthe maximum prediction size when the size of the image block is greaterthan the maximum prediction size, where a size of the N split imageblocks is the same as the maximum prediction size, and a coding unit,configured to perform simplified depth coding SDC on the N split imageblocks using the intra-frame prediction mode.

With reference to the fourth aspect, in a first possible implementationmanner, the determining unit is configured to split the image block toobtain split image blocks according to the size of the image block andthe maximum prediction size, where if a size of the split image blocksis the same as the maximum prediction size, the N split image blocks areobtained, or if a size of the split image blocks is greater than themaximum prediction size, continue to split the split image blocks untilthe size of the split image blocks is the same as the maximum predictionsize, and the N split image blocks are obtained.

With reference to the fourth aspect or the first possible implementationmanner, in a second possible implementation manner, the coding unit isconfigured to determine an average value of prediction data of the Nsplit image blocks using the intra-frame prediction mode and determinean average value of raw data of the N split image blocks, determineresiduals of the N split image blocks according to the average value ofthe prediction data of the N split image blocks and the average value ofthe raw data of the N split image blocks, and code the residuals of theN split image blocks, so as to complete performing simplified depthcoding SDC on the N split image blocks.

With reference to the second possible implementation manner, in a thirdpossible implementation manner, the coding unit is configured todetermine the prediction data of the N split image blocks using theintra-frame prediction mode, and determine the average value of theprediction data of the N split image blocks using the following formula,PV_(i)=ΣPPix_(i)[x,y]/sumOfPPix, where PV_(i) is an average value ofprediction data of the i^(th) image block among the N split imageblocks, PPix₁ [x,y] is a pixel value in prediction data whosecoordinates are [x,y] in the i^(th) image block, and sumOfPPix is thenumber of pixels in the i^(th) image block.

With reference to the second possible implementation manner, in a fourthpossible implementation manner, the coding unit is configured todetermine the average value of the raw data of the N split image blocksusing the following formula, BV_(i)=ΣBPix_(i)[x,y]/sumOfBPix, where BVis an average value of raw data of the i^(th) image block among the Nsplit image blocks, BPix_(i)[x,y] is a pixel value in raw data whosecoordinates are [x,y] in the i^(th) image block, and sumOfBPix is thenumber of pixels in the i^(th) image block.

With reference to the second possible implementation manner, in a fifthpossible implementation manner, the coding unit is configured todetermine the residuals of the N split image blocks using the followingformula, S_(i)=PV_(i)−BV_(i), where S_(i) is a residual of the i^(th)image block among the N split image blocks, PV_(i) is an average valueof prediction data of the i^(th) image block among the N split imageblocks, and BV_(i) is an average value of raw data of the i^(th) imageblock among the N split image blocks.

With reference to the fourth aspect, in a sixth possible implementationmanner, the determining unit is further configured to, when the size ofthe image block is less than or equal to the maximum prediction size,perform simplified depth coding SDC on the image block according to theintra-frame prediction mode.

According to the embodiments of the present disclosure, when coding ordecoding is performed on an image block on which SDC is performed, asame intra-frame prediction mode can be adopted to code and decode Nimage blocks that belong to the image block. In this way, processingefficiency of coding and decoding can be improved.

According to a fifth aspect, an embodiment of the present disclosureprovides a method for decoding a depth map, where the method includesdetermining a size of an image block and a maximum prediction size, in acase in which the size of the image block is greater than the maximumprediction size, determining that a signaling bit has N bit, anddetermining, according to the signaling bit, an intra-frame predictionmode that is used when the SDC is performed on the image block, and in acase in which the size of the image block is less than or equal to themaximum prediction size, determining that the signaling bits have Mbits, and determining, according to the signaling bits, that a mode thatis used when the SDC is performed on the image block is the directcurrent mode or the planar mode, where a value of M is greater than thatof N.

With reference to the fifth aspect, in a first possible implementationmanner, the intra-frame prediction mode is a direct current mode or aplanar mode or a depth modeling mode DMM.

According to a sixth aspect, an embodiment of the present disclosureprovides a method for coding a depth map, where the method includesdetermining a size of an image block and a maximum prediction size,selecting an intra-frame prediction mode, in a case in which the size ofthe image block is greater than the maximum prediction size,determining, when the SDC is performed on the image block, that N bit isused as a signaling bit that identifies the intra-frame prediction mode,or in a case in which the size of the image block is less than or equalto the maximum prediction size, determining, when the SDC is performedon the image block, that M bits are used as signaling bits that identifythe intra-frame prediction mode, where a value of M is greater than thatof N.

With reference to the sixth aspect, in a first possible implementationmanner, the intra-frame prediction mode is a direct current mode or aplanar mode or a depth modeling mode DMM.

According to a seventh aspect, an embodiment of the present disclosureprovides an apparatus for decoding a depth map, where the decodingapparatus includes a determining unit, configured to determine a size ofan image block and a maximum prediction size, and a decoding unit,configured to, in a case in which the size of the image block is greaterthan the maximum prediction size, determine that a signaling bit has Nbit, and determine, according to the signaling bit, an intra-frameprediction mode that is used when the SDC is performed on the imageblock, and in a case in which the size of the image block is less thanor equal to the maximum prediction size, determine that the signalingbits have M bits, and determine, according to the signaling bits, that amode that is used when the SDC is performed on the image block is thedirect current mode or the planar mode, where a value of M is greaterthan that of N.

According to an eighth aspect, an embodiment of the present disclosureprovides an apparatus for coding a depth map, where the coding apparatusincludes a determining unit, configured to determine a size of an imageblock and a maximum prediction size, and a coding unit, configured todetermine an intra-frame prediction mode, where the coding unit isfurther configured to, in a case in which the size of the image block isgreater than the maximum prediction size, determine, when the SDC isperformed on the image block, that N bit is used as a signaling bit thatidentifies the intra-frame prediction mode, or in a case in which thesize of the image block is less than or equal to the maximum predictionsize, determine, when the SDC is performed on the image block, that Mbits are used as signaling bits that identify the intra-frame predictionmode, where a value of M is greater than that of N.

According to a ninth aspect, an embodiment of the present disclosureprovides a method for decoding a depth map, where the method includesdetermining a size of an image block and a maximum prediction size, in acase in which the size of the image block is greater than the maximumprediction size, determining an intra-frame prediction mode that is usedwhen the SDC is performed on the image block, and in a case in which thesize of the image block is less than or equal to the maximum predictionsize, determining that signaling bits have M bits, and determining,according to the signaling bits, an intra-frame prediction mode that isused when the SDC is performed on the image block.

With reference to the ninth aspect, in a first possible implementationmanner, the intra-frame prediction mode is a direct current mode or aplanar mode or a depth modeling mode DMM.

According to a tenth aspect, an embodiment of the present disclosureprovides an apparatus for decoding a depth map, where the decodingapparatus includes a determining unit, configured to determine a size ofan image block and a maximum prediction size, and a decoding unit,configured to, in a case in which the size of the image block is greaterthan the maximum prediction size, determine an intra-frame predictionmode that is used when the SDC is performed on the image block, and in acase in which the size of the image block is less than or equal to themaximum prediction size, determine that signaling bits have M bits, anddetermine, according to the signaling bits, an intra-frame predictionmode that is used when the SDC is performed on the image block.

With reference to the tenth aspect, in a first possible implementationmanner, the intra-frame prediction mode is a direct current mode or aplanar mode or a depth modeling mode DMM.

According to the methods provided in the embodiments of the presentdisclosure, when coding or decoding is performed on a depth map, thenumber of bits of signaling bits that are used to identify anintra-frame prediction mode can be reduced, thereby achieving objectivesof reducing resources and accelerating coding and decoding.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe the technical solutions in the embodiments of the presentdisclosure more clearly, the following briefly introduces theaccompanying drawings required for describing the embodiments of thepresent disclosure. Apparently, the accompanying drawings in thefollowing description show merely some embodiments of the presentdisclosure, and a person of ordinary skill in the art may still deriveother drawings from these accompanying drawings without creativeefforts.

FIG. 1 is a schematic flowchart of a method for decoding a depth mapaccording to an embodiment of the present disclosure.

FIG. 2 is a schematic flowchart of a method for decoding a depth mapaccording to an embodiment of the present disclosure.

FIG. 3 is a schematic flowchart of a method for coding a depth mapaccording to an embodiment of the present disclosure.

FIG. 4 is a schematic flowchart of a method for coding a depth mapaccording to an embodiment of the present disclosure.

FIG. 5 is a schematic diagram of a method for coding and decoding adepth map according to an embodiment of the present disclosure.

FIG. 6 is a schematic flowchart of another method for decoding a depthmap according to an embodiment of the present disclosure.

FIG. 7 is a schematic flowchart of another method for coding a depth mapaccording to an embodiment of the present disclosure.

FIG. 8 is a structural block diagram of an apparatus for decoding adepth map according to an embodiment of the present disclosure.

FIG. 9 is a structural block diagram of an apparatus for coding a depthmap according to an embodiment of the present disclosure.

FIG. 10 is a structural block diagram of another apparatus for decodinga depth map according to an embodiment of the present disclosure.

FIG. 11 is a structural block diagram of another apparatus for coding adepth map according to an embodiment of the present disclosure.

FIG. 12 is a structural block diagram of an apparatus for decoding adepth map according to an embodiment of the present disclosure.

FIG. 13 is a structural block diagram of an apparatus for coding a depthmap according to an embodiment of the present disclosure.

FIG. 14 is a structural block diagram of another apparatus for decodinga depth map according to an embodiment of the present disclosure.

FIG. 15 is a structural block diagram of another apparatus for coding adepth map according to an embodiment of the present disclosure.

FIG. 16 is a structural block diagram of a decoding apparatus accordingto an embodiment of the present disclosure.

DETAILED DESCRIPTION

The following clearly describes the technical solutions in theembodiments of the present disclosure with reference to the accompanyingdrawings in the embodiments of the present disclosure. Apparently, thedescribed embodiments are merely some but not all of the embodiments ofthe present disclosure. All other embodiments obtained by a person ofordinary skill in the art based on the embodiments of the presentdisclosure without creative efforts shall fall within the protectionscope of the present disclosure.

FIG. 1 is a schematic flowchart of a method for decoding a depth mapaccording to an embodiment of the present disclosure.

101. Obtain a flag of SDC and determine to perform SDC decoding.

102. Determine a size of an image block and a maximum prediction size.

103. Determine an intra-frame prediction mode of the image block.

In an embodiment, a prediction mode that can be used when the SDC isperformed on the image block may be any one of the following modes adirect current mode, a planar mode, and a DMM, where the DMM includes anexplicit wedgelet mode, an intra-predicted wedgelet partitioning mode,an inter-component prediction of wedgelet partitioning mode, and aninter-component prediction of contour partitioning mode.

104. In a case in which the size of the image block is greater than themaximum prediction size, split the image block to obtain N split imageblocks according to the size of the image block and the maximumprediction size, where a size of each of the N split image blocks is thesame as the maximum prediction size.

105. Perform the SDC decoding on each of the N split image blocks usingthe intra-frame prediction mode.

According to the method shown in FIG. 1, when decoding is performed onan image block on which SDC is performed, a same intra-frame predictionmode can be adopted to decode N image blocks that belong to the imageblock. In this way, processing efficiency of reconstructing, by adecoder, an image block of a depth map on which SDC coding is performedcan be improved.

FIG. 2 is a schematic flowchart of a method for decoding a depth mapaccording to an embodiment of the present disclosure.

201. Obtain a flag of SDC and determine to perform SDC decoding.

202. Determine a size of an image block and a maximum prediction size.

203. Determine an intra-frame prediction mode of the image block.

In an embodiment, a prediction mode that can be used when the SDC isperformed on the image block may be any one of the following modes adirect current mode, a planar mode, and a DMM, where the DMM includes anexplicit wedgelet mode, an intra-predicted wedgelet partitioning mode,an inter-component prediction of wedgelet partitioning mode, and aninter-component prediction of contour partitioning mode.

204. In a case in which the size of the image block is greater than themaximum prediction size, split the image block to obtain N split imageblocks according to the size of the image block and the maximumprediction size, where a size of each of the N split image blocks is thesame as the maximum prediction size.

Optionally, it may be determined that N is a square of a ratio of thesize of the image block to the maximum prediction size. For example, thesize of the image block is 64, and the maximum prediction size is 32, inthis case, the ratio between the two is 2, and a value of N is 4.

Optionally, during the splitting of the image block, the image block mayalso be split, in a recursive splitting manner, to obtain N predictionblocks. The image block is split to obtain split image blocks accordingto the size of the image block and the maximum prediction size. If asize of each of the split image blocks is the same as the maximumprediction size, the N split image blocks are obtained, or if a size ofeach of the split image blocks is greater than the maximum predictionsize, the split image blocks continue to be split until the size of eachof the split image blocks is the same as the maximum prediction size,and the N split image blocks are obtained.

In an embodiment, the size of the image block is compared with themaximum prediction size, and if the size of the image block is greaterthan the maximum prediction size, the image block is split into multipleimage blocks of an equal size. Generally, the image block is split intofour image blocks, where each of the split image blocks is half of theimage block in width and height, or each of the split image blocks isthe same as the image block in width and a quarter of the image block inheight, or each of the split image blocks is the same as the image blockin height and a quarter of the image block in width. Then a size of eachof the multiple split image blocks is compared with the maximumprediction size, and if the size of the multiple split image blocks isgreater than the maximum prediction size, the foregoing step isrepeated, that is, each of the split image blocks is further split untila size of image blocks that are obtained by means of splitting is thesame as the maximum prediction size, and the split image blocks whosesize is the same as the maximum prediction size serve as image blocksthat are used when the SDC is performed.

In the foregoing step, the size of the image block is obtained from adecoding process, and the maximum prediction size is obtained from abitstream by decoding.

In addition, a prediction process of intra-frame coding is bound with atransform process of the intra-frame coding, and therefore intra-frameprediction may be performed based on a size of a transform block duringthe intra-frame prediction, that is, the size of the image block isconsistent with the size of the transform block. Therefore, the size ofthe image block mentioned in the present disclosure may also berepresented by the size of the transform block, and the maximumprediction size may also be represented by a maximum transform size. Inan embodiment, it is supposed that log2TrafoSize is the size of theimage block, and Log2MaxTrafoSize is the maximum prediction size, whereboth log2TrafoSize and Log2MaxTrafoSize are represented in a form of alogarithm of a block size, that is, the size of the image block equals 2log2TrafoSize, and the maximum prediction size equals 2Log2MaxTrafoSize. When 1 is subtracted from a value of log2TrafoSize orLog2MaxTrafoSize, it identifies that a corresponding block size isdivided by 2. When log2TrafoSize is greater than Log2MaxTrafoSize, acurrent transform block is split into four transform blocks of a smallersize, where the size of each of the four transform blocks islog2TrafoSize−1, then the foregoing splitting is performed on each ofthe split transform blocks according to Log2MaxTrafoSize until it isdetermined that the value of log2TrafoSize equals the value ofLog2MaxTrafoSize. In this case, the intra-frame prediction is performedbased on Log2MaxTrafoSize.

It may be understood that other manners may also be adopted to split theimage block to obtain the N split image blocks, and the size of each ofthe N split image blocks is the same as the maximum prediction size. Allthese methods for splitting an image block fall within the protectionscope of the present disclosure.

205. Determine prediction data of each of the N image blocks using theintra-frame prediction mode that is used when the SDC is performed onthe image block.

206. Repeatedly use a formula 2.1 until an average value of theprediction data of each of the N image blocks is determined.

PV _(i) =PPix_(i)[x,y]/sumOfPPix   2.1,

where

PV_(i) is an average value of prediction data of the i^(th) image blockamong the N image blocks, PPix_(i)[x,y] is a pixel value in predictiondata whose coordinates are [x,y] in the i^(th) image block, andsumOfPPix is the number of pixels in the i^(th) image block.

207. Obtain N residuals by means of decoding when the SDC decoding isperformed on each of the N split image blocks.

In an embodiment, a coder codes a residual of the image block whenperforming the SDC coding and determines a data stream that includes theresidual of the image block. In a case in which a decoder receives thedata stream that includes the residual of the image block, the decoderdecodes the data stream and determines a residual of each of the N imageblocks that belong to the image block. It may be understood that step207 may also be performed before step 206, which is not limited in thepresent disclosure.

208. Determine a reconstruction value of each of the N image blocksaccording to the average value of the prediction data of each of the Nimage blocks and the residual of each of the N image blocks, so as tocomplete performing the decoding on each of the N image blocks.

In an embodiment, a formula 2.2 may be repeatedly used until thereconstruction value of each of the N image blocks is determined.

R _(i) =PV _(i) +S _(i)  2.2, where

R_(i) is a reconstruction value of the i^(th) image block among the Nimage blocks, PV_(i) is prediction data of the i^(th) image block amongthe N image blocks, and S′ is a residual of the i^(th) image block amongthe N image blocks.

209. Reconstruct the image block according to a result of the decodingperformed on each of the N image blocks. In an embodiment, determine,according to the reconstruction value of each of the N image blocks, areconstructed image of the image block on which the SDC coding isperformed.

It may be understood that step 204 to step 209 are performed in the casein which the size of the image block on which the SDC is performed isgreater than the maximum prediction size. In a case in which the size ofthe image block on which the SDC is performed is less than or equal tothe maximum prediction size, the decoder may directly use theintra-frame prediction mode to perform the SDC decoding on the imageblock.

According to the method shown in FIG. 2, when decoding is performed onan image block on which SDC is performed, a same intra-frame predictionmode can be adopted to decode N image blocks that belong to the imageblock. In this way, processing efficiency of reconstructing, by adecoder, an image block of a depth map on which SDC coding is performedcan be improved.

FIG. 3 is a schematic flowchart of a method for coding a depth mapaccording to an embodiment of the present disclosure.

301. Determine a size of an image block and a maximum prediction size,where the image block is an image block of a depth map on which SDCneeds to be performed.

302. Determine an intra-frame prediction mode.

In an embodiment, a prediction mode that can be used may be any one ofthe following modes a direct current mode, a planar mode, and a DMM,where the DMM includes an explicit wedgelet mode, an intra-predictedwedgelet partitioning mode, an inter-component prediction of wedgeletpartitioning mode, and an inter-component prediction of contourpartitioning mode.

303. In a case in which the size of the image block is greater than themaximum prediction size, split the image block to obtain N split imageblocks according to the size of the image block and the maximumprediction size, where a size of each of the N split image blocks is thesame as the maximum prediction size.

304. Perform the SDC on each of the N split image blocks using theintra-frame prediction mode.

According to the method shown in FIG. 3, in the case in which the sizeof the image block is greater than the maximum prediction size, a sameintra-frame prediction mode can be used to perform the SDC on each ofthe N split image blocks. In this way, efficiency of processing, by acoder, an image block of a depth map on which the SDC coding needs to beperformed can be greatly improved.

FIG. 4 is a schematic flowchart of a method for coding a depth mapaccording to an embodiment of the present disclosure. FIG. 4 is aspecific embodiment of the method for coding a depth map in FIG. 3.

401. Determine a size of an image block of a depth map on which SDCneeds to be performed and a maximum prediction size.

402. Determine an intra-frame prediction mode.

In an embodiment, a prediction mode that can be used may be any one ofthe following modes a direct current mode, a planar mode, and a DMM,where the DMM includes an explicit wedgelet mode, an intra-predictedwedgelet partitioning mode, an inter-component prediction of wedgeletpartitioning mode, and an inter-component prediction of contourpartitioning mode.

403. In a case in which the size of the image block is greater than themaximum prediction size, split the image block to obtain N split imageblocks according to the size of the image block and the maximumprediction size, where a size of each of the N split image blocks is thesame as the maximum prediction size.

During the splitting of the image block, the image block may be split,in a recursive splitting manner, to obtain N prediction blocks. Theimage block is split to obtain split image blocks according to the sizeof the image block and the maximum prediction size. If a size of each ofthe split image blocks is the same as the maximum prediction size, the Nsplit image blocks are obtained, or if the size of each of the splitimage blocks is greater than the maximum prediction size, the splitimage blocks continue to be split until the size of each of the splitimage blocks is the same as the maximum prediction size, and the N splitimage blocks are obtained.

In the foregoing step, the size of the image block is obtained from adecoding process, and the maximum prediction size is obtained from abitstream by decoding.

In an embodiment, the size of the image block is compared with themaximum prediction size, and if the size of the image block is greaterthan the maximum prediction size, the image block is split into multipleimage blocks of an equal size. Generally, the image block is split intofour image blocks, where each of the split image blocks is half of theimage block in width and height, or each of the split image blocks isthe same as the image block in width and a quarter of the image block inheight, or each of the split image blocks is the same as the image blockin height and a quarter of the image block in width. Then a size of eachof the multiple split image blocks is compared with the maximumprediction size, and if the size of the multiple split image blocks isgreater than the maximum prediction size, the foregoing step isrepeated, that is, each of the split image blocks is further split untila size of image blocks that are obtained by means of splitting is thesame as the maximum prediction size, and the split image blocks whosesize is the same as the maximum prediction size serve as image blocksthat are used when the SDC is performed.

In addition, a prediction process of intra-frame coding is bound with atransform process of the intra-frame coding, and therefore intra-frameprediction may be performed based on a size of a transform block duringthe intra-frame prediction, that is, the size of the image block isconsistent with the size of the transform block. Therefore, the size ofthe image block mentioned in the present disclosure may also berepresented by the size of the transform block, and the maximumprediction size may also be represented by a maximum transform size. Inan embodiment, it is supposed that log2TrafoSize is the size of theimage block, and Log2MaxTrafoSize is the maximum prediction size, whereboth log2TrafoSize and Log2MaxTrafoSize are represented in a form of alogarithm of a block size, that is, the size of the image block equals 2log2TrafoSize, and the maximum prediction size equals 2Log2MaxTrafoSize. When 1 is subtracted from a value of log2TrafoSize orLog2MaxTrafoSize, it identifies that a corresponding block size isdivided by 2. When log2TrafoSize is greater than Log2MaxTrafoSize, acurrent transform block is split into four transform blocks of a smallersize, where the size of each of the four transform blocks islog2TrafoSize−1, then the foregoing splitting is performed on each ofthe split transform blocks according to Log2MaxTrafoSize until it isdetermined that the value of log2TrafoSize equals the value ofLog2MaxTrafoSize. In this case, the intra-frame prediction is performedbased on Log2MaxTrafoSize.

It may be understood that other manners may also be adopted to split theimage block to obtain the N split image blocks, and the size of each ofthe N split image blocks is the same as the maximum prediction size. Allthese methods for splitting an image block fall within the protectionscope of the present disclosure.

404. Determine prediction data of each of the N split image blocks usingthe intra-frame prediction mode.

In an embodiment, a same intra-frame prediction mode is used when apixel value in the prediction data of each of the N split image blocksis determined, for example, the direct current mode is used, or theinter-component prediction of wedgelet partitioning mode, which is aDMM, is used.

405. Repeatedly use a formula 4.1 until an average value of theprediction data of each of the N split image blocks is determined.

PV _(i) =ΣPPix_(i)[x,y]/sumOfPPix  4.1,

where PV_(i) is an average value of prediction data of the i^(th) imageblock among the N split image blocks, PPix₁ [x,y] is a pixel value inprediction data whose coordinates are [x,y] in the i^(th) image block,and sumOfPPix is the number of pixels in the i^(th) image block.

406. Repeatedly use a formula 4.2 until an average value of raw data ofeach of the N split image blocks is determined.

BV _(i) =ΣBPix_(i)[x,y]/sumOfBPix,   4.2,

where BV_(i) is an average value of raw data of the i^(th) image blockamong the N split image blocks, BPix_(i)[x,y] is a pixel value in rawdata whose coordinates are [x,y] in the i^(th) image block, andsumOfBPix is the number of pixels in the i^(th) image block.

407. Determine a residual of each of the N split image blocks accordingto the average value of the prediction data of each of the N split imageblocks and the average value of the raw data of each of the N splitimage blocks.

In an embodiment, a formula 4.3 is repeatedly used until the residual ofeach of the N split image blocks is determined.

S _(i) =PV _(i) −BV _(i)  4.3, where

S_(i) is a residual of the i^(th) image block among the N split imageblocks, PV_(i) is an average value of prediction data of the i^(th)image block among the N split image blocks, and BV_(i) is an averagevalue of raw data of the i^(th) image block among the N split imageblocks.

408. Perform coding on each of the N split image blocks, so as tocomplete performing the SDC on each of the N split image blocks.

Further, a coder may further notify a decoder of the intra-frameprediction mode that is used when the SDC is performed.

It may be understood that step 403 to step 408 are performed in the casein which the size of the image block is greater than the maximumprediction size. If the size of the image block is less than or equal tothe maximum prediction size, the coder may use the intra-frameprediction mode to perform the SDC on the image block.

According to the method shown in FIG. 4, in the case in which the sizeof the image block is greater than the maximum prediction size, a sameintra-frame prediction mode can be used to perform the SDC on each ofthe N split image blocks. In this way, efficiency of processing, by acoder, an image block of a depth map on which the SDC coding needs to beperformed can be greatly improved.

FIG. 5 is a schematic diagram of a method for coding and decoding adepth map according to an embodiment of the present disclosure.

As shown in FIG. 5, SDC needs to be performed on an image block 500. Asize of the image block 500 is 64×64p, where p represents pixel (Pix). Amaximum prediction size is 32×32p. In this case, the image block 500 maybe split into four image blocks, 501, 502, 503, and 504. According tothe formula 4.1, formula 4.2, and formula 4.3, it may be calculated thataverage values of prediction data of 501, 502, 503, and 504 is PV₁, PV₂,PV₃, and PV₄ respectively, average values of P₁, P₂, P₃, and P₄ are BV₁,BV₂, BV₃, and respectively, and residuals of 501, 502, 503, and 504 areS₁, S₂, S₃, and S₄ respectively. Then S₁, S₂, S₃ and S₄ are coded, so asto complete a process of performing the SDC on the image block 500.

Accordingly, when decoding is performed on the image block 500 on whichthe SDC coding is performed, a decoder may calculate, according to theformula 2.1 and formula 2.2, that the prediction data of 501, 502, 503,and 504 is PV₁, PV₂, PV₃, and PV₄ respectively, and reconstructionvalues of 501, 502, 503, and 504 are R₁, R₂, R₃, and R₄ respectively. Inthis way, the decoder may determine a reconstructed image block 500according to the reconstruction values, that is, a SDC decoding processis completed.

FIG. 6 is a schematic flowchart of another method for decoding a depthmap according to an embodiment of the present disclosure.

601. Determine a size of an image block and a maximum prediction size.

602. In a case in which the size of the image block is greater than themaximum prediction size, determine that a signaling bit has N bit, anddetermine, according to the signaling bit, an intra-frame predictionmode that is used when SDC is performed on the image block. For example,in a case in which a decoder determines that the signaling bit has 1bit, if the signaling bit is 0, the decoder may determine that a directcurrent mode is used when the SDC is performed on the image block, ifthe signaling bit is 1, the decoder may determine that a planar mode isused when the SDC is performed on the image block.

603. In a case in which the size of the image block is less than orequal to the maximum prediction size, determine that signaling bits haveM bits, and determine, according to the signaling bits, that a mode thatis used when the SDC is performed on the image block is the directcurrent mode or the planar mode, where a value of M is greater than thatof N, and both M and N are positive integers. For example, in the casein which the size of the image block is less than or equal to themaximum prediction size, it is determined that 2 bits are used assignaling bits that identify a selected mode. For example, if thesignaling bits are 00, the decoder may determine that the intra-frameprediction mode that is used when the SDC is performed on the imageblock is the direct current mode. If the signaling bits are 10, thedecoder may determine that the intra-frame prediction mode that is usedwhen the SDC is performed on the image block is the planar mode. If thesignaling bits are 11, the decoder may determine that the intra-frameprediction mode that is used when the SDC is performed on the imageblock is an explicit identifier-based wedgelet mode, which is a DMM.

It may be understood that the intra-frame prediction mode may be theplanar mode or the direct current mode or the DMM.

In the foregoing example, if there are only two candidate modes, such asthe planar mode and the explicit identifier-based wedgelet mode, in thecase in which the size of the image block is greater than the maximumprediction size, a value of N in the N bits is 0, that is, the decodermay determine, without a need of an identifier, the intra-frameprediction mode that is used in the SDC, such as the planar mode. In thecase in which the size of the image block is less than or equal to themaximum prediction size, a value of M in the M bits is 1, theintra-frame prediction mode that is used in the SDC is determinedaccording to the value of M, for example, 0 indicates that the explicitidentifier-based wedgelet mode is used, and 1 indicates that the planarmode is used.

In arithmetic coding (Arithmetic Coding), all syntax elements are codedin a form of a binary symbol, for example, in the foregoing example, inthe case in which the size of the image block is less than or equal tothe maximum prediction size, “the signaling bits being 10” indicates theplanar mode, and in this case, the signaling bits “10” are a binarysymbol of the arithmetic coding.

Apparently, another embodiment of the present disclosure may furtherprovide a method for decoding a depth map, where the method includesdetermining a size of an image block and a maximum prediction size, in acase in which the size of the image block is greater than the maximumprediction size, determining an intra-frame prediction mode that is usedwhen the SDC is performed on the image block, and in a case in which thesize of the image block is less than or equal to the maximum predictionsize, determining that signaling bits have M bits, and determining,according to the signaling bits, an intra-frame prediction mode that isused when the SDC is performed on the image block.

Optionally, the intra-frame prediction mode is a direct current mode ora planar mode or a depth modeling mode DMM.

A person skilled in the art may clearly learn from the foregoingimplementation manner that in the case in which the size of the imageblock is greater than the maximum prediction size, the implementationmanner of determining that the signaling bit has N bit and determining,according to the signaling bit, the intra-frame prediction mode that isused when the SDC is performed on the image block is not mandatory, andin the case in which the size of the image block is greater than themaximum prediction size, the intra-frame prediction mode that is usedwhen the SDC is performed on the image block may be directly determined.The scope described in this embodiment of the present disclosure isstill included in the protection scope of the specific implementationmanner shown in FIG. 6.

Accordingly, another embodiment of the present disclosure may furtherprovide an apparatus for decoding a depth map, where the decodingapparatus includes a determining unit, configured to determine a size ofan image block and a maximum prediction size, and a decoding unit,configured to, in a case in which the size of the image block is greaterthan the maximum prediction size, determine an intra-frame predictionmode that is used when the SDC is performed on the image block, and in acase in which the size of the image block is less than or equal to themaximum prediction size, determine that signaling bits have M bits, anddetermine, according to the signaling bits, an intra-frame predictionmode that is used when the SDC is performed on the image block.

Optionally, the intra-frame prediction mode is a direct current mode ora planar mode or a depth modeling mode DMM.

According to the method shown in FIG. 6, when a decoder performs SDCdecoding, the number of bits of signaling bits that are used to identifyan intra-frame prediction mode can be reduced, thereby achievingobjectives of reducing resources and accelerating decoding.

FIG. 7 is a schematic flowchart of another method for coding a depth mapaccording to an embodiment of the present disclosure.

701. Determine a size of an image block and a maximum prediction size.

702. Select an intra-frame prediction mode.

In an embodiment, the intra-frame prediction mode may be a directcurrent mode or a planar mode or a DMM.

703. In a case in which the size of the image block is greater than themaximum prediction size, determine, when SDC is performed on the imageblock, that N bit is used as a signaling bit that identifies theintra-frame prediction mode.

In an embodiment, the signaling bit being 0 indicates that theintra-frame prediction mode that is used when the SDC is performed onthe image block is the direct current mode. The signaling bit being 1indicates that the intra-frame prediction mode that is used when the SDCis performed on the image block is the planar mode.

704. In a case in which the size of the image block is less than orequal to the maximum prediction size, determine, when the SDC isperformed on the image block, that M bits are used as signaling bitsthat identify the intra-frame prediction mode, where a value of M isgreater than that of N, and both M and N are positive integers.

In an embodiment, it is determined that 2 bits are used as the signalingbits that identify the selected mode. For example, the signaling bitsbeing 00 indicates that the intra-frame prediction mode that is usedwhen the SDC is performed on the image block is the direct current mode.The signaling bits being 10 indicates that the intra-frame predictionmode that is used when the SDC is performed on the image block is theplanar mode. The signaling bits being 11 indicates that the intra-frameprediction mode that is used when the SDC is performed on the imageblock is the explicit identifier-based wedgelet mode, which is a DMM.

Optionally, as another embodiment, in a case in which it is determinedthat the size of the image block is greater than the maximum predictionsize of intra-frame prediction, a coder does not use the SDC mode toperform coding on the image block of the depth map. Accordingly, adecoder does not use the SDC mode to perform decoding on the image blockof the depth map either.

According to the method shown in FIG. 7, when a coder performs SDCcoding, the number of bits of signaling bits that are used to identifyan intra-frame prediction mode can be reduced, thereby achieving anobjective of reducing resources.

FIG. 8 is a structural block diagram of an apparatus for decoding adepth map according to an embodiment of the present disclosure. Thedecoding apparatus 800 shown in FIG. 8 may perform each step shown inFIG. 1 or FIG. 2, and the decoding apparatus 800 includes a determiningunit 801, a decoding unit 802, and a reconstructing unit 803.

The determining unit 801 is configured to determine, according to a flagof SDC, to perform SDC decoding.

The determining unit 801 is further configured to determine a size of animage block and a maximum prediction size.

The determining unit 801 is further configured to determine anintra-frame prediction mode that is used when SDC is performed on theimage block.

The determining unit 801 is further configured to split the image blockto obtain N split image blocks according to the size of the image blockand the maximum prediction size when the size of the image block isgreater than the maximum prediction size, where a size of each of the Nsplit image blocks is the same as the maximum prediction size.

The decoding unit 802 is configured to perform the SDC decoding on eachof the N split image blocks using the intra-frame prediction mode.

The reconstructing unit 803 is configured to reconstruct the image blockaccording to a result of the decoding performed on each of the N imageblocks.

As shown in FIG. 8, when the decoding apparatus 800 decodes an imageblock on which SDC is performed, a same intra-frame prediction mode canbe adopted to decode N image blocks that belong to the image block. Inthis way, processing efficiency of reconstructing, by the decodingapparatus 800, an image block of a depth map on which SDC coding isperformed can be improved.

In an embodiment, the determining unit 801 is configured to split theimage block to obtain split image blocks according to the size of theimage block and the maximum prediction size, where if a size of each ofthe split image blocks is the same as the maximum prediction size, the Nsplit image blocks are obtained, or if the size of each of the splitimage blocks is greater than the maximum prediction size, continue tosplit the split image blocks until the size of each of the split imageblocks is the same as the maximum prediction size, and the N split imageblocks are obtained.

In an embodiment, the decoding unit 802 is configured to obtain Nresiduals by means of decoding when performing the SDC decoding on eachof the N split image blocks.

In an embodiment, the decoding unit 802 is configured to determine anaverage value of prediction data of each of the N image blocks anddetermine a residual of each of the N image blocks using the intra-frameprediction mode that is used when the SDC is performed on the imageblock, and determine a reconstruction value of each of the N imageblocks according to the average value of the prediction data of each ofthe N image blocks and the residual of each of the N image blocks, so asto complete performing the decoding on performed on each of the N imageblocks.

In an embodiment, the decoding unit 802 is configured to determine theprediction data of each of the N image blocks using the intra-frameprediction mode that is used when the SDC is performed on the imageblock, and determine the average value of the prediction data of each ofthe N image blocks using the following formula,PV_(i)=ΣPPix_(i)[x,y]/sumOfPPix where PV_(i) is an average value ofprediction data of the i^(th) image block among the N image blocks,PPix_(i)[x,y] is a pixel value in prediction data whose coordinates are[x,y] in the i^(th) image block, and sumOfPPix is the number of pixelsin the i^(th) image block.

In an embodiment, the decoding unit 802 is configured to determine thereconstruction value of each of the N image blocks using the followingformula R_(i)=PV_(i)+S_(i), where R_(i) is a reconstruction value of thei^(th) image block among the N image blocks, PV_(i) is an average valueof prediction data of the i^(th) image block among the N image blocks,and S_(i) is a residual of the i^(th) image block among the N imageblocks.

FIG. 9 is a structural block diagram of an apparatus for coding a depthmap according to an embodiment of the present disclosure. The codingapparatus 900 shown in FIG. 9 may perform each step in FIG. 3 or FIG. 4,and the coding apparatus 900 includes a determining unit 901 and acoding unit 902.

The determining unit 901 is configured to determine a size of an imageblock and a maximum prediction size.

The determining unit 901 is further configured to determine anintra-frame prediction mode.

The determining unit 901 is further configured to split the image blockto obtain N split image blocks according to the size of the image blockand the maximum prediction size when the size of the image block isgreater than the maximum prediction size, where a size of each of the Nsplit image blocks is the same as the maximum prediction size.

The coding unit 902 is configured to perform SDC on each of the N splitimage blocks using the intra-frame prediction mode.

As shown in FIG. 9, in a case in which the size of the image block isgreater than the maximum prediction size, the coding apparatus 900 mayperform the SDC on each of the N split image blocks using a sameintra-frame prediction mode. In this way, efficiency of processing, bythe coding apparatus 900, an image block of a depth map on which the SDCcoding needs to be performed can be greatly improved.

Optionally, the determining unit 901 is configured to split, in arecursive splitting manner, the image block to obtain the N split imageblocks according to the size of the image block and the maximumprediction size.

In an embodiment, the coding unit 902 is configured to determine anaverage value of prediction data of each of the N split image blocks anddetermine an average value of raw data of each of the N split imageblocks using the intra-frame prediction mode, determine a residual ofeach of the N split image blocks according to the average value of theprediction data of each of the N split image blocks and the averagevalue of the raw data of each of the N split image blocks, and code theresidual of each of the N split image blocks, so as to completeperforming simplified depth coding SDC on each of the N split imageblocks.

In an embodiment, the coding unit 902 is configured to determine a pixelvalue in the prediction data of each of the N split image blocks usingthe intra-frame prediction mode, and determine the average value of theprediction data of each of the N split image blocks using the followingformula, PV_(i)=ΣPPix_(i)[x,y]/sumOfPPix, where PV_(i) is an averagevalue of prediction data of the i^(th) image block among the N splitimage blocks, PPix_(i)[x,y] is a pixel value in prediction data whosecoordinates are [x,y] in the i^(th) image block, and sumOfPPix is thenumber of pixels in the i^(th) image block.

In an embodiment, the coding unit 902 is configured to determine theaverage value of the raw data of each of the N split image blocks usingthe following formula, BV_(i)=ΣBPix_(i)[x,y]/sunmOfBPix, where BV_(i) isan average value of raw data of the i^(th) image block among the N splitimage blocks, BPix [x,y] is a pixel value in raw data whose coordinatesare [x,y] in the i^(th) image block, and sumOfBPix is the number ofpixels in the i^(th) image block.

In an embodiment, the coding unit is configured to determine theresidual of each of the N split image blocks using the followingformula, S_(i)=PV_(i)−BV_(i) where S_(i) is a residual of the i^(th)image block among the N split image blocks, PV_(i) is an average valueof prediction data of the i^(th) image block among the N image blocks,and BV_(i) is an average value of raw data of the i^(th) image blockamong the N image blocks.

Optionally, the determining unit 901 is further configured to determinethe intra-frame prediction mode when the size of the image block is lessthan or equal to the maximum prediction size. The coding unit 902 isfurther configured to perform the SDC on the image block according tothe intra-frame prediction mode.

FIG. 10 is a structural block diagram of another apparatus for decodinga depth map according to an embodiment of the present disclosure. Asshown in FIG. 10, the decoding apparatus 1000 includes a determiningunit 1001 and a decoding unit 1002.

The determining unit 1001 is configured to determine a size of an imageblock and a maximum prediction size.

The decoding unit 1002 is configured to, in a case in which the size ofthe image block is greater than the maximum prediction size, determinethat a signaling bit has N bit, and determine, according to thesignaling bit, an intra-frame prediction mode that is used when SDC isperformed on the image block.

The decoding unit 1002 is further configured to, in a case in which thesize of the image block is less than or equal to the maximum predictionsize, determine that the signaling bits have M bits, and determine,according to the signaling bits, that a mode that is used when the SDCis performed on the image block is a direct current mode or a planarmode, where a value of M is greater than or equal to N, and both M and Nare positive integers.

As shown in FIG. 10, when the decoding apparatus 1000 performs SDCdecoding, the number of bits of signaling bits that are used to identifyan intra-frame prediction mode can be reduced, thereby achievingobjectives of reducing resources and accelerating decoding.

FIG. 11 is a structural block diagram of another apparatus for coding adepth map according to an embodiment of the present disclosure. As shownin FIG. 11, the coding apparatus 1100 includes a determining unit 1101and a coding unit 1102.

The determining unit 1101 is configured to determine a size of an imageblock and a maximum prediction size.

The coding unit 1102 is configured to select an intra-frame predictionmode.

The coding unit 1102 is further configured to, in a case in which thesize of the image block is greater than the maximum prediction size,determine, when SDC is performed on the image block, that N bit is usedas a signaling bit that identifies the intra-frame prediction mode.

The coding unit 1102 is further configured to, in a case in which thesize of the image block is less than or equal to the maximum predictionsize, determine, when the SDC is performed on the image block, that Mbits are used as signaling bits that identify the intra-frame predictionmode.

As shown in FIG. 11, when the coding apparatus 1100 performs SDC coding,the number of bits of signaling bits that are used to identify anintra-frame prediction mode can be reduced, thereby achieving anobjective of reducing resources.

FIG. 12 is a structural block diagram of an apparatus for decoding adepth map according to an embodiment of the present disclosure. Thedecoding apparatus 1200 may perform each step of the decoding method inFIG. 1 or FIG. 2. The decoding apparatus 1200 shown in FIG. 12 mayperform each step in FIG. 1 or FIG. 2, and the decoding apparatus 1200includes a memory 1201 and a processor 1202.

The memory 1201 is configured to store a decoding algorithm of a depthmap so that the processor 1202 performs SDC decoding on the depth mapaccording to the decoding algorithm.

The processor 1202 is configured to determine, according to a flag ofSDC, to perform the SDC decoding.

The processor 1202 is further configured to determine a size of an imageblock and a maximum prediction size.

The processor 1202 is further configured to determine an intra-frameprediction mode that is used when SDC is performed on the image block.

The processor 1202 is further configured to split the image block toobtain N split image blocks according to the size of the image block andthe maximum prediction size in a case in which the size of the imageblock is greater than the maximum prediction size, where a size of eachof the N split image blocks is the same as the maximum prediction size.

The processor 1202 is further configured to perform the SDC decoding oneach of the N split image blocks using the intra-frame prediction mode.

The processor 1202 is configured to reconstruct the image blockaccording to a result of the decoding performed on each of the N imageblocks.

As shown in FIG. 12, when the decoding apparatus 1200 performs decodingon an image block on which SDC is performed, a same intra-frameprediction mode can be adopted to decode N image blocks that belong tothe image block. In this way, processing efficiency of reconstructing,by the decoding apparatus 1200, an image block of a depth map on whichSDC coding is performed can be improved.

In an embodiment, the processor 1202 is configured to split the imageblock to obtain split image blocks according to the size of the imageblock and the maximum prediction size, where if a size of each of thesplit image blocks is the same as the maximum prediction size, the Nsplit image blocks are obtained, or if the size of each of the splitimage blocks is greater than the maximum prediction size, continue tosplit the split image blocks until the size of each of the split imageblocks is the same as the maximum prediction size, and the N split imageblocks are obtained.

In an embodiment, the processor 1202 is configured to determine anaverage value of prediction data of each of the N image blocks anddetermine a residual of each of the N image blocks using the intra-frameprediction mode that is used when the SDC is performed on the imageblock, and determine a reconstruction value of each of the N imageblocks according to the average value of the prediction data of each ofthe N image blocks and the residual of each of the N image blocks, so asto complete performing the decoding on performed on each of the N imageblocks.

In an embodiment, the processor 1202 is configured to determine theprediction data of each of the N image blocks using the intra-frameprediction mode that is used when the SDC is performed on the imageblock, and determine the average value of the prediction data of each ofthe N image blocks using the following formula,PV_(i)=ΣPPix_(i)[x,y]/sumOfPPix, where PV_(i) is an average value ofprediction data of the i^(th) image block among the N image blocks,PPix_(i)[x,y] is a pixel value in prediction data whose coordinates are[x,y] in the i^(th) image block, and sumOfPPix is the number of pixelsin the i^(th) image block.

In an embodiment, the processor 1202 is configured to determine thereconstruction value of each of the N image blocks using the followingformula, R_(i)=PV_(i)+S_(i), where R_(i) is a reconstruction value ofthe i^(th) image block among the N image blocks, PV_(i) is an averagevalue of prediction data of the i^(th) image block among the N imageblocks, and S_(i) is a residual of the i^(th) image block among the Nimage blocks.

FIG. 13 is a structural block diagram of an apparatus for coding a depthmap according to an embodiment of the present disclosure. The codingapparatus 1300 may perform each step of the coding method in FIG. 3 orFIG. 4. The coding apparatus 1300 shown in FIG. 13 may perform each stepin FIG. 3 or FIG. 4, and the coding apparatus 1300 includes a memory1301 and a processor 1302.

The memory 1301 is configured to store a coding algorithm of a depth mapso that the processor performs SDC according to the algorithm.

The processor 1302 is configured to determine a size of an image blockand a maximum prediction size.

The processor 1302 is further configured to determine an intra-frameprediction mode.

The processor 1302 is further configured to split the image block toobtain N split image blocks according to the size of the image block andthe maximum prediction size when the size of the image block is greaterthan the maximum prediction size, where a size of each of the N splitimage blocks is the same as the maximum prediction size.

The processor 1302 is configured to perform the SDC on each of the Nsplit image blocks using the intra-frame prediction mode.

As shown in FIG. 13, in a case in which the size of the image block isgreater than the maximum prediction size, the coding apparatus 1300 mayperform the SDC on each of the N split image blocks using a sameintra-frame prediction mode. In this way, efficiency of processing, bythe coding apparatus 1300, an image block of a depth map on which theSDC coding needs to be performed can be greatly improved.

Optionally, the processor 1302 is configured to split, in a recursivesplitting manner, the image block to obtain the N split image blocksaccording to the size of the image block and the maximum predictionsize.

In an embodiment, the processor 1302 is configured to determine anaverage value of prediction data of each of the N split image blocks anddetermine an average value of raw data of each of the N split imageblocks using the intra-frame prediction mode, determine a residual ofeach of the N split image blocks according to the average value of theprediction data of each of the N split image blocks and the averagevalue of the raw data of each of the N split image blocks, and code theresidual of each of the N split image blocks, so as to completeperforming simplified depth coding SDC on each of the N split imageblocks.

In an embodiment, the processor 1302 is configured to determine a pixelvalue in the prediction data of each of the N split image blocks usingthe intra-frame prediction mode, and determine the average value of theprediction data of each of the N split image blocks using the followingformula, PV_(i)=ΣPPix_(i)[x,y]/sumOfPPix, where PV_(i) is an averagevalue of prediction data of the i^(th) image block among the N splitimage blocks, PPix_(i)[x,y] is a pixel value in prediction data whosecoordinates are [x,y] in the i^(th) image block, and sumOfPPix is thenumber of pixels in the i^(th) image block.

In an embodiment, the processor 1302 is configured to determine theaverage value of the raw data of each of the N split image blocks usingthe following formula, BV_(i)=ΣBPix_(i)[x,y]/sunmOfBPix, where BV is anaverage value of raw data of the i^(th) image block among the N splitimage blocks, BPixx_(i)[x,y] is a pixel value in raw data whosecoordinates are [x,y] in the i^(th) image block, and sumOfBPix is thenumber of pixels in the i^(th) image block.

In an embodiment, the coding unit is configured to determine theresidual of each of the N split image blocks using the followingformula, S_(i)=PV_(i)−BV_(i), where S_(i) is a residual of the i^(th)image block among the N split image blocks, PV_(i) is an average valueof prediction data of the i^(th) image block among the N image blocks,and BV_(i) is an average value of raw data of the i^(th) image blockamong the N image blocks.

Optionally, the processor 1302 is further configured to determine theintra-frame prediction mode when the size of the image block is lessthan or equal to the maximum prediction size. The processor 1302 isfurther configured to perform the SDC on the image block according tothe intra-frame prediction mode.

FIG. 14 is a structural block diagram of another apparatus for decodinga depth map according to an embodiment of the present disclosure. Thedecoding apparatus 1400 may perform each step of the decoding method inFIG. 6. As shown in FIG. 14, the decoding apparatus 1400 includes amemory 1401 and a processor 1402.

The memory 1401 is configured to store a decoding algorithm of a depthmap so that the processor 1402 performs SDC decoding on the depth mapaccording to the decoding algorithm.

The processor 1402 is configured to determine a size of an image blockand a maximum prediction size.

The processor 1402 is further configured to, in a case in which the sizeof the image block is greater than the maximum prediction size,determine that a signaling bit has N bit, and determine, according tothe signaling bit, an intra-frame prediction mode that is used when SDCis performed on the image block.

The processor 1402 is further configured to, in a case in which the sizeof the image block is less than or equal to the maximum prediction size,determine that the signaling bits have M bits, and determine, accordingto the signaling bits, that a mode that is used when the SDC isperformed on the image block is a direct current mode or a planar mode,where a value of M is greater than or equal to N, and both M and N arepositive integers.

As shown in FIG. 14, when the decoding apparatus 1400 performs SDCdecoding, the number of bits of signaling bits that are used to identifyan intra-frame prediction mode can be reduced, thereby achievingobjectives of reducing resources and accelerating decoding.

FIG. 15 is a structural block diagram of another apparatus for coding adepth map according to an embodiment of the present disclosure. Thecoding apparatus 1500 may perform each step of the coding method in FIG.7. As shown in FIG. 15, the coding apparatus 1500 includes a memory 1501and a processor 1502.

The memory 1501 is configured to store a coding algorithm of a depth mapso that the processor 1502 performs SDC on the depth map according tothe coding algorithm.

The processor 1502 is configured to determine a size of an image blockand a maximum prediction size.

The processor 1502 is further configured to determine an intra-frameprediction mode.

The processor 1502 is further configured to, in a case in which the sizeof the image block is greater than the maximum prediction size,determine, when SDC is performed on the image block, that N bit is usedas a signaling bit that identifies the intra-frame prediction mode.

The coding unit 1502 is further configured to, in a case in which thesize of the image block is less than or equal to the maximum predictionsize, determine, when the SDC is performed on the image block, that Mbits are used as signaling bits that identify the intra-frame predictionmode.

As shown in FIG. 15, when the coding apparatus 1500 performs SDC coding,the number of bits of signaling bits that are used to identify anintra-frame prediction mode can be reduced, thereby achieving anobjective of reducing resources.

FIG. 16 is a structural block diagram of a decoding apparatus accordingto an embodiment of the present disclosure. The decoding apparatus 1600may perform each step of the decoding method in FIG. 1 or FIG. 2. Thedecoding apparatus 1600 includes an entropy decoding unit 1601, aninverse scanning unit 1602, a dequantization unit 1603, an inversetransformation unit 1604, a prediction unit 1605, a combination unit1606, and a frame storage component 1607.

The decoding apparatus 1600 may be located in a handheld terminal devicesuch as a mobile phone and a tablet computer, and a wearable terminaldevice with a video playing function, and may also be located in anapparatus such as a notebook computer, a desktop computer, and a mediaprocessing function node on a communications network.

When a bitstream generated by a coder passes through the entropydecoding unit 1601, the entropy decoding unit 1601 performs entropydecoding processing on the bitstream and obtains a group ofreconstruction values of prediction errors and header information(including motion information), where the group of the reconstructionvalues of the prediction errors may be considered as a 1-dimensionalcoefficient vector, then the 1-dimensional coefficient vector passesthrough the inverse scanning unit 1602, and the inverse scanning 1602performs inverse scanning processing to obtain a 2-dimensionalcoefficient block, the 2-dimensional coefficient block undergoesdequantization processing of the dequantization unit 1603 and inversetransformation processing of the inverse transformation unit 1604, and aprediction error of a target area is obtained, and the headerinformation undergoes processing of the prediction unit 1605, and finalprediction value of the target area is obtained.

For the foregoing processing process, refer to the method for decoding adepth map provided in the embodiments of the present disclosure. Thecombination unit 1606 combines the prediction error and the finalprediction value to obtain a reconstructed block, and the reconstructedblock is stored by the frame storage component 1607, may be displayed ona display of an apparatus such as the mobile phone and the notebookcomputer during video playing, and may also assist in determining of thefinal prediction value when the prediction unit 1605 subsequentlyprocesses the header information.

Specially, in this embodiment of the present disclosure, the functionsof the decoding unit 802 in FIG. 8 may be implemented by the entropydecoding unit 1601 of the decoding apparatus 1600, and all the functionsof the determining unit 801 may be implemented by the prediction unit1605 of the decoding apparatus 1600.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm steps may be implemented byelectronic hardware or a combination of computer software and electronichardware. Whether the functions are performed by hardware or softwaredepends on particular applications and design constraint conditions ofthe technical solutions. A person skilled in the art may use differentmethods to implement the described functions for each particularapplication, but it should not be considered that the implementationgoes beyond the scope of the present disclosure.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, reference may bemade to a corresponding process in the foregoing method embodiments, anddetails are not described herein again.

In the several embodiments provided in the present application, itshould be understood that the disclosed system, apparatus, and methodmay be implemented in other manners. For example, the describedapparatus embodiment is merely exemplary. For example, the unit divisionis merely logical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented through some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of the presentdisclosure may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit.

When the functions are implemented in the form of a software functionalunit and sold or used as an independent product, the functions may bestored in a computer-readable storage medium. Based on such anunderstanding, the technical solutions of the present disclosureessentially, or a part of the technical solutions may be implemented ina form of a software product. The software product is stored in astorage medium and includes several instructions for instructing acomputer device (which may be a personal computer, a server, or anetwork device) or a processor to perform all or a part of the steps ofthe methods described in the embodiments of the present disclosure. Theforegoing storage medium includes any medium that can store programcode, such as a Universal Serial Bus (USB) flash drive, a removable harddisk, a read-only memory (ROM), a random-access memory (RAM), a magneticdisk, or an optical disc.

The foregoing descriptions are merely specific embodiments of thepresent disclosure, but are not intended to limit the protection scopeof the present disclosure. Any variation or replacement readily figuredout by a person skilled in the art within the technical scope disclosedin the present disclosure shall fall within the protection scope of thepresent disclosure. Therefore, the protection scope of the presentdisclosure shall be subject to the protection scope of the claims.

What is claimed is:
 1. A method for simplified depth decoding,comprising: obtaining a flag of simplified depth coding (SDC), wherein avalue of the flag indicates that SDC decoding is used for an imageblock; determining an intra prediction mode of the image block;splitting the image block to obtain N split image blocks when a size ofthe image block is greater than a maximum prediction size, wherein asize of each of the N split image blocks is the same as the maximumprediction size; obtaining a residual when performing the SDC decodingon an i^(th) split image block of the N split image blocks; obtainingprediction data of the i^(th) split image block using the intraprediction mode that is used when the SDC is performed on the imageblock; determining an average value of the prediction data based on aplurality of pixel values in the prediction data and a number of pixelsin the i^(th) split image block; and determining a reconstruction valueof the i^(th) split image block according to the average value of theprediction data and the residual to perform the SDC decoding on thei^(th) split image block.
 2. The method of claim 1, wherein the intraprediction mode is a depth modeling mode (DMM), a planar mode, or adirect current mode.
 3. The method of claim 1, wherein splitting theimage block to obtain the N split image blocks comprises: splitting theimage block to obtain split image blocks according to the size of theimage block and the maximum prediction size; obtaining the N split imageblocks when a size of the split image blocks is the same as the maximumprediction size; and further splitting the split image blocks until thesize of the split image blocks is the same as the maximum predictionsize when a size of the split image blocks is greater than the maximumprediction size to obtain the N split image.
 4. The method of claim 1,wherein the average value of the prediction data of the i^(th) splitimage block is determined based on the following formula:PV _(i) =ΣPPix_(i)[x,y]/sumOfPPix, wherein PV_(i) is the average valueof the prediction data of the i^(th) split image block, PPix_(i)[x,y] isa pixel value in the prediction data with coordinates that are [x,y] inthe i^(th) split image block, and sumOfPPix is the number of pixels inthe i^(th) split image block.
 5. The method of claim 1, wherein thereconstruction value of the i^(th) split image block is determined basedon the following formula:R _(i) =PV _(i) +S _(i) wherein R_(i) is the reconstruction value of thei^(th) split image block, PV_(i) is the average value of the predictiondata of the i^(th) split image block, and S_(i) is a residual of thei^(th) split image block among the N split image blocks.
 6. A method forsimplified depth coding (SDC), comprising: determining an intraprediction mode of the image block; splitting the image block to obtainN split image blocks when a size of the image block is greater than amaximum prediction size, wherein a size of the N split image blocks isthe same as the maximum prediction size; and determining prediction dataof an i^(th) split image block of the N split image blocks using theintra prediction mode; determining an average value of the predictiondata based on a plurality of pixel values in the prediction data of thei^(th) split image block and a number of pixels in the i^(th) splitimage block; determining an average value of raw data of the i^(th)split image block; determining a residual of the i^(th) split imageblock according to the average value of the prediction data and theaverage value of the raw data; and coding the residual of the i^(th)split image block to perform SDC on the i^(th) split image block.
 7. Themethod of claim 6, wherein the-intra prediction mode is a depth modelingmode (DMM), a planar mode, or a direct current mode.
 8. The method ofclaim 6, wherein splitting the image block to obtain N split imageblocks comprises: splitting the image block to obtain split image blocksaccording to the size of the image block and the maximum predictionsize; obtaining the N split image blocks when a size of the split imageblocks is the same as the maximum prediction size; and further splittingthe split image blocks until the size of the split image blocks is thesame as the maximum prediction size when a size of the split imageblocks is greater than the maximum prediction size to obtain the N splitimage.
 9. The method of claim 6, wherein the average value of theprediction data is determined based on the following formula:PV _(i) =ΣPPix_(i)[x,y]/sumOfPPix, wherein PV_(i) is the average valueof the prediction data of the i^(th) split image block, PPix_(i)[x,y] isa pixel value in the prediction data with coordinates that are [x,y] inthe i^(th) split image block, and sumOfPPix is the number of pixels inthe i^(th) split image block.
 10. The method of claim 6, wherein theaverage value of the raw data is determined based on the followingformula:BV _(i) =ΣBPix_(i)[x,y]/sumOfBPix, wherein BV_(i) is the average valueof raw data of the i^(th) split image block, BPix_(i)[x,y] is a pixelvalue in the raw data with coordinates that are [x,y] in the i^(th)split image block, and sumOfBPix is the number of pixels in the i^(th)split image block.
 11. The method of claim 6, wherein the residual ofthe i^(th) split image block is determined based on the followingformula:S _(i) =PV _(i) −BV _(i), wherein S_(i) is the residual of the i^(th)split image block, PV_(i) is the average value of the prediction data,and BV_(i) is the average value of raw data.
 12. The method of claim 6,further comprising performing SDC on the image block according to theintra prediction mode when the size of the image block is less than orequal to the maximum prediction size.
 13. A decoding apparatuscomprising: a memory storing instructions; and a processor configured toexecute the instructions to: determine to use simplified depth coding(SDC) decoding according to a flag of SDC; determine an intra predictionmode that is used when SDC is performed on the image block; split theimage block to obtain N split image blocks when a size of the imageblock is greater than a maximum prediction size, wherein a size of the Nsplit image blocks is the same as the maximum prediction size and the Nsplit image blocks are all transform blocks; obtain a residual whenperforming the SDC decoding on an i^(th) split image block of the Nsplit image blocks; obtain prediction data of the i^(th) split imageblock by using the intra prediction mode that is used when the SDC isperformed on the image block; determine an average value of theprediction data based on a plurality of pixel values in the predictiondata and a number of pixels in the i^(th) split image block; anddetermine a reconstruction value of the i^(th) split image blockaccording to the average value of the prediction data and the residualto perform the SDC decoding on the i^(th) split image block.
 14. Thedecoding apparatus of claim 13, wherein the processor is furtherconfigured to execute the instructions to: split the image block toobtain split image blocks according to the size of the image block andthe maximum prediction size; obtain the N split image blocks when a sizeof the split image blocks is the same as the maximum prediction size;and further split the split image blocks until the size of the splitimage blocks is the same as the maximum prediction size when a size ofthe split image blocks is greater than the maximum prediction size toobtain the N split image blocks.
 15. The decoding apparatus of claim 13,wherein the processor is further configured to execute the instructionsto determine the average value of the prediction data based on thefollowing formula:PV _(i) =ΣPPix_(i)[x,y]/sumOfPPix, wherein PV_(i) is the average valueof the prediction data, PPix_(i)[x,y] is a pixel value in the predictiondata with coordinates that are [x,y] in the i^(th) split image block,and sumOfPPix is the number of pixels in the i^(th) split image block.16. The decoding apparatus of claim 13, wherein the processor is furtherconfigured to execute the instructions to determine the reconstructionvalue of the i^(th) split image block based on the following formula:R _(i) =PV _(i) +S _(i), wherein R_(i) is the reconstruction value ofthe i^(th) split image block, PV_(i) is the average value of theprediction data, and S_(i) is a residual of the i^(th) split image blockamong the N split image blocks.
 17. A coding apparatus for simplifieddepth coding (SDC), comprising: a memory storing instructions; and aprocessor configured to execute the instructions to: determine an intraprediction mode of the image block; split the image block to obtain Nsplit image blocks when a size of the image block is greater than amaximum prediction size, wherein a size of the N split image blocks isthe same as the maximum prediction size; determine prediction data of ani^(th) split image block of the N split image blocks using the intraprediction mode; determine an average value of the prediction data basedon a plurality of pixel values in the prediction data of the i^(th)split image block and a number of pixels in the i^(th) split imageblock; determine an average value of raw data of the i^(th) split imageblock; determine a residual of the i^(th) split image block according tothe average value of the prediction data and the average value of theraw data; and code the residual of the i^(th) split image block toperform SDC on the i^(th) split image block.
 18. The coding apparatus ofclaim 17, wherein the processor is further configured to execute theinstructions to: split the image block to obtain split image blocksaccording to the size of the image block and the maximum predictionsize; obtain the N split image blocks when a size of the split imageblocks is the same as the maximum prediction size; and further split thesplit image blocks until the size of the split image blocks is the sameas the maximum prediction size when a size of the split image blocks isgreater than the maximum prediction size to obtain the N split imageblocks.
 19. The coding apparatus according to claim 17, wherein theprocessor is further configured to execute the instructions to determinethe average value of the prediction data of the i^(th) split image blockbased on the following formula:PV _(i) =ΣPPix_(i)[x,y]/sumOfPPix, wherein PV_(i) is the average valueof the prediction data, PPix_(i)[x,y] is a pixel value in the predictiondata with coordinates that are [x,y] in the i^(th) split image block,and sumOfPPix is the number of pixels in the i^(th) split image block.20. The coding apparatus according to claim 17, wherein the processor isfurther configured to execute the instructions to determine the averagevalue of the raw data of the i^(th) split image block based on thefollowing formula:BV _(i) =ΣBPix_(i)[x,y]/sumOfBPix, wherein BV_(i) is the average valueof raw data, BPix_(i)[x,y] is a pixel value in the raw data withcoordinates that are [x,y] in the i^(th) split image block, andsumOfBPix is the number of pixels in the i^(th) split image block. 21.The coding apparatus according to claim 17, wherein the processor isfurther configured to execute the instructions to determine the residualof the i^(th) split image block based on the following formula:S _(i) =PV _(i) −BV _(i), wherein S_(i) is the residual of the i^(th)split image block, PV_(i) is the average value of the prediction data,and BV_(i) is the average value of raw data.
 22. The coding apparatusaccording to claim 17, wherein the instructions further cause theprocessor to be configured to perform SDC on the image block accordingto the intra prediction mode when the size of the image block is lessthan or equal to the maximum prediction size.